This invention relates to temperature control in aquariums.
Aquariums are habitats for a wide variety of aquatic life. While it is common knowledge that some life, for example tropical fish, require heated water for survival, it is less well known that if the water temperature exceeds a certain limit, it is as harmful for the aquatic life as water which is too cold. All one has to consider is that fish life downstream from the cooling water discharge ports of power plants is killed by a rise in temperature that is only a few degrees to understand that a small rise in temperature can be detrimental. Part of the problem stems from the fact that oxygen dissolves in water in amounts that are a function of the water temperature. It is therefore important to maintain the water temperature in an aquarium within a narrow range of temperature.
Although it is relatively easy to provide local heating to raise the temperature of the water in an aquarium to be within the required range, cooling the aquarium has been a problem. Typically no cooling has been provided and the keepers of an aquarium have generally relied on the maintenance of the temperature of the room in which the aquarium is located to provide the required cooling. For rooms without airconditioning, aquarium keepers have resorted to fans or placing ice cubes in the aquarium water, to lower its temperature. However, even for those with airconditioned rooms, it becomes less reasonable to cool the room simply to maintain the temperature of the aquarium, as the cost of electricity increases and electrical shortages appear. It is more reasonable to cool the aquarium alone, rather than to cool the room in which the aquarium is situated.
Previous attempts at cooling the aquarium have required larger refrigeration units than could reasonably be used in a home setting. The patent of Harwood (U.S. Pat. No. 3,855,970) discloses an aquarium which includes a heat exchanger and a refrigeration unit to maintain the temperature. The referigeration unit in this patent included a refrigeration compressor and so this is not the ideal solution for use in the home setting.
The present invention discloses a refrigeration means for an aquarium which is suitable for home use.